The ease of setup with perfectmail! It's so much easier than other competitors out there in this space (SpamTitan). I did not like that it was more expensive per user compared to others but we were able have many users at once which made up some difference over time as our mail volume increased. We've been using perfectly email since 2006 without any major issues or complaints from customers until now when suddenly one day they started receiving all sorts emails including phishing attempts etc.. Our customer base has grown significantly during these past years - mostly due to word-of mouth marketing by satisfied happy clients who tell their friends about us too!! So i'm sure if you're looking into an anti SPAM software then look no further because your search will end here!! They are great people working hard everyday solving problems related to internet security!